REL has four subwoofer lines. They range from the "Habitat1" lifestyle products to the "Gibraltar" subs which are their finest offerings. The T-9 is the biggest sub from REL's "Serie T" line. The T subs are the most affordable floor standing REL subs and they are generally intended for home cinema applications.

The T-9 is roughly cubic in shape and checks in at just under 15" a side. Its main driver is a down-firing 10" "bass engine" with a stamped steel frame and a coated paper cone. REL refers to this as an "Ultra Long Throw" driver and I can attest that it has a generous surround. The main driver is loaded by a 10" coated paper passive radiator that is mounted on the front of the cabinet.

REL claims their drivers are carefully designed to reproduce low bass, with exceptionally low resonant frequencies and long-travel suspensions. They refer to them as "bass engines". REL also claims that they keep the moving mass as low as practical in their drivers, thereby making for a more mechanically efficient design. One can infer from these claims that the drivers' suspensions are highly flexible to maintain acceptably low free air resonance frequencies.

Built-in amplification for the T-9 is by way of a high current 300W Class A/B amp with remote-mounted toroidal transformer. This amp is cooled via an oversized heat sink bank. Three connection options are available: unbalanced low level, unbalanced .1 LFE and a balanced high level input via an included high level cable with a Neutrik Speakon connector that snaps into the back of the amp. I will further discuss this connection in the following Set-Up section of this review.

There are separate volume controls for the low and high level inputs. The non-defeatable second-order variable low-pass filter utilizes Butterworth filtering and is set via an analog dial with a range from 30 – 120 Hz.

REL makes the following claim regarding the T-9 – "REL's latest input filter design is borrowed from its more expensive sibling (Serie R) and is considerably quicker than previous REL designs. This speed is partly responsible for the slam and attack for which Serie T is known."

The REL T-9 cabinet is solidly braced and features a high gloss finish with five layers of carefully applied lacquer. The T-9s are available in either black or white finishes. One last point – the sub comes with milled aluminum feet and no spikes. It is plug and play ready.